The general recommendation is that your hot water system should be replaced every 8 to 12 years.
Hot water tanks are generally made from steel or stainless steel. On the inside, your hot water tank is usually lined with a protective enamel coating. Over time this enamel breaks down and once this occurs it’s possible for your water tank to start rusting and breaking down. The water is in direct contact with the steel.
Any rust or sediment within your tank has no way to escape so it accumulates in the bottom of your hot water tank, forming a brown sludge. The water in a hot water tank is “non-potable” (non-drinkable) and for good reason. When water is heated any natural sediment within the water also drops to the bottom.
It is quite shocking to see the sludge that lurks in the bottom of old water tanks. Check out this video showing what we regularly drain out of old hot water heaters throughout Brisbane and the Gold Coast.